Project Summary (GVVC) As one of three Stanford Neuroscience Cores, the Gene Vector and Virus Core (GVVC) provides viral vectors to manipulate and express recombinant proteins in the whole brain, in slices, and in cellular systems in a temporally and spatially controlled manner. The ability to employ these molecular techniques is essential to the daily research activities of a significant number of neuroscience labs at Stanford, and with the continued development of new molecular tools to report on and to manipulate neuronal function, and to trace neuronal connections with greater specificity, these techniques will remain critical to advancing our progress in understanding brain function. Over the past 4 years the GVVC has made 1348 viruses and provided 219 pre- made stock viruses for 581 projects. Moreover, GVVC has supported the viral production for the innovative optogenetics technology, in which light-sensitive channels (channelrhodopsins) are used to regulate neuronal activity, invented by the Dr. Karl Deisseroth laboratory. Logistical proximity of GVVC and its support for Deisseroth laboratory has led to dissemination of this technology not only to Stanford faculty but to many other neuroscientists nationwide. Since its inception, GVVC has continued to add to the number of stock viruses in its virus repository (http://med.stanford.edu/gvvc/stockviruses.html) which is accessible for distribution. Under the proposed grant, GVVC will continue to provide its present cutting-edge services. In addition, GVVC will develop new services, such as CAV-2 (canine adenovirus) virus, that will allow retrograde axonal transportation.